query re IPv6 URL format

Francis Dupont Francis.Dupont@inria.fr
Tue, 14 Oct 1997 21:08:33 +0200


 In your previous mail you wrote:

   Brian,
   
   >If that was the decision then we need to codify it and tell
   >the world. I could live with it, if the URL parsers can handle
   >it. I'll check that with the URL guys.
   >
   
   Maybe I am missing something, but...
   
   The IPv4 syntax is:
   
   	http://111.222.333.444/~bc
   
   It would seem to me that while
   
   	http://aaaa:bbbb::cccc:dddd/~bc
   
   has multiple ":"'s in it, given left to right parsing, I don't see anything
   ambiguous.  The first thing after the "//" is either a DNS name, IPv4
   address, or an IPv6 address.  If the current parsers can distinguish
   between "hursley.ibm.com" and "111.222.333.444", both of which use dots as
   separators, then could they also deal with IPv6 addresses with colons?
   
=> it is not true (just look at the RFC 1738 or for instance lynx
documentation). According to the last one, URLs can be:

http://host:port/path?searchpart#fragment
           ^
telnet://user:password@host:port
             ^             ^

ftp://username:password@host:port/path;type=[D,I, or A]
              ^             ^
...
And dont' forget we need the same thing for RFC 821/822, X11, ...

   Why can't the parsers learn how to do this?  They need to be changed to
   handle IPv6 addresses anyway.
   
=> it is very easy and as far as I know enough to support DNS names
(and the terrible RES_USE_INET6 stuff). Personally I think the right
thing to do is to kill literals (IPv4 literals too)!

Regards

Francis.Dupont@inria.fr

PS: the URL format http://host:port/... is very common and perhaps
will become more common if ISPs put a bad priority to the 80 TCP port (:-).